1. Field of the Invention
The present invention relates to an apparatus and method for reproducing an optical recording medium, and more particularly, to an apparatus and method for detecting a position of a pickup using information regarding a rotational speed of a disc at a wobble speed factor, which is a different type of recording speed factor when recording a signal on the disc that can store up to 90 minutes of data and holds repeating location information.
2. Description of the Related Art
In general, as shown in FIG. 1, a 90-minute optical disc includes three signal areas: a lead-in area, a program area, and a lead-out area. The lead-in area includes information recorded on the optical disc, such as information regarding a position, a type, and reproduction time thereof. The lead-in area is called a table of contents (TOC) area, and a TOC signal is repeatedly recorded in the lead-in area. A reproduction signal is recorded in the program area, and the lead-out area is a signal area that indicates a termination of a program. Referring to FIG. 1, except for a 99-minute disc, a 90–99 minute area is present only in the lead-in area. Thus, when a pickup is to be positioned in an area of 95 or more minutes, the area is regarded as being the lead-in area and access to the lead-in area begins.
However, in the case of an up-to-90 minute optical disc, the 90–99 minute area is present in both the lead-in area and the program area, as shown in FIG. 2. That is, in the optical disc having capacity of 90 minutes or more, location information, which is recorded in an absolute time-code in pre-groove (ATIP), is repeatedly recorded in the lead-in area and the program area. Therefore, there can be a case where a current location of the pickup cannot be precisely detected using only the location information decoded in the ATIP. When a signal is recorded on the optical disc, it is possible to easily reproduce the signal based on the location information recorded in a Sub-Q code. However, in the case of a recording device, the location information recorded in the ATIP is used to record the signal on the optical disc on which data or the signal is not recorded. Therefore, if the location information is read from outermost and innermost sections where the ATIP location information is repeatedly recorded, the same values are obtained, thereby making it difficult to detect a precise location of the pickup without additional information.